Screw-propeller for flying machines and other aerodynamics apparatus



P. FOOT I May 31 1932.

SCREW PROPELLER FOR FLYING MACHINES AND OTHER AERODYNMIICS APPARATUSFiled June 19. 1931 Patented May 31, 1932 UNITED STATES PATENT OFFICEPHILIPPE PO01, OF SAVENTHEM, BELGIUM.

Application filed June 19, 1931, Serial No.

I have made foreign applications as fol-' lows: in Belgium, on August18th, 1930, No. 37 2,767; in Germany, on April 20th, 1931.

My present invention relates to screw-pro- 5 pellers for flying machinesand other aerodynamics apparatus and it has for its object to provide animproved screw-propeller of this type, that is one in which the wingsare undulated or waved in. the plane parallel to the axis of thepropeller as well as at right angles to said axis.

A further object of my invention is to provide a screw-propeller of thetype described, in which the axes of the wave troughs for the innerwaves or undulations coincide with a circumference the center of whichis located on the hub member of the propeller on the extension of thebase line of the Wave troughs, whilst for the outer wave troughs theaxes of 29 the troughs coincide with a circumference the centre of whichis located on the extension of the front edge line of the propellerwing.

Other objects and advantages of my invention will appear from thefollowing disclosure taken in connection with the accompanying drawingsshowing by way of example one preferred embodiment of my invention andin which:

Fig. 1 is a front elevation of a screw-propeller having two alinedwings.

Fig. 2 is a diagrammatica'l cross section thereof, showing the differentpitches of the screw threads.

Referring more particularly to the drawings, my improved screw-propelleris constructed with two or more combined pitches. Each wing of thescrew-propeller is limited on the side turned towards the wind by astraight line 1 el, whilst the rear edge 2-3 thereof is undulated orwaved in the plane parallel to the axis 11 as well as at right anglesthereto. The peaks or crests are designated by the numeral 2 and thetroughs by the numeral 3. The wave troughs 3 are made of conical shapeand the apexes thereof are turned towards the straight edge 1-4, that istowards the wind. The axes of these wave troughs correspond: for theinner waves or undulations to a circumference 6 the centre 9 of which islocated on the cen- 545,509, and in Belgium August 18, 1930.

tral portion or hub member 7 of the screw propeller on the extension ofthe base line 8, and for the outer Wave troughs to a circun1- ference 5the centre 10 of which'is located a on the extension of the. front wingedge a. Owing to this particular arrangement the vacuum in front of thepropeller Wing will be highly increased, whereby an increase of theaction of the pressure existing at the rear of the wing will beobtained.

Referring more particularly to Fig. 2 of the drawings, the section linel2, representwill be saved and on the other hand the energy driving thescrew wings forwardly will be reduced.

Minor details of the construction described and shown may be changed ormodified as desired without departing from the scope of my invention.

I claim:

In a screw-propeller for flying machines and other aerodynamicsapparatus having a plurality of wings, the combination with each wingbody, of undulations or waves formed in said body parallel to the axisof the screw-propeller as well as at right angles thereto, the axes ofthe inner wave troughs coinciding with a circumferencethe centre ofwhich is located on the central portion or hub member of thescrew-propeller on the extension of the base line of said troughs,Whilst the axes of the outer wave troughs coincide with a circumferencethe centre of which is located on the extension of the front straightedge line of the wing body, substantially as set forth.

PHILIPPE POOT.

